Channels in two types of systems were studied. One system is the wheat protoplast - a wheat cell whose cell wall has been removed - and the other is the BTX-modified sodium channel in neuroblastoma cells. In the wheat protoplast, using single-channel techniques, we found several different types of channels, including a voltage-dependent channel. In our study of BTX-modified sodium channels, we examined patches of membrane containing two channels and found that the closing rates of two channels within the same patch are very similar, in contrast to our previous finding that the closing rates of channels from different patches differ by as much as an order of magnitude.